1. Field of the Invention
The present invention relates to a system and method for an initiator oscillator for use in tire pressure monitoring systems.
2. Background Art
It is known in the automotive industry to provide for wireless monitoring of vehicle tire parameters, particularly tire pressure. In such tire pressure monitoring systems, tire pressure sensors and radio frequency (RF) transmitters including initiators that have high frequency pre-driver and signal conditioning circuitry. In each tire, at least one signal that corresponds to the tire pressure sensed by the tire pressure sensor is processed by the high frequency pre-driver and signal conditioning circuitry (e.g., initiator oscillator circuitry) prior to being transmitted by the transmitter through an antenna to a receiver/controller located on the vehicle. The tire pressure information delivered to the receiver/controller by the RF signals from the transmitters is subsequently conveyed to a vehicle operator or occupant, typically using a display unit. In such a fashion, tire pressure monitoring systems can help to improve vehicle safety. Exemplary tire pressure monitoring systems are described and shown in U.S. Pat. Nos. 6,112,587 and 6,034,597.
Some conventional approaches to initiator oscillators (or generators) as implemented in tire pressure monitoring systems use expensive microprocessors to achieve the desired oscillator frequency generation accuracy and data generation. Additionally, some conventional approaches to initiator generators as implemented in tire pressure monitoring systems use double-ended enable input circuitry. Conventional microprocessor controlled circuitry and double-ended circuitry can be expensive to implement.
Thus, there exists a need for a system and a method for a low frequency initiation generator (e.g., high frequency pre-driver and signal conditioning circuitry) for use in a tire pressure monitoring system that achieves the desired frequency accuracy at a lower cost than conventional microprocessor based approaches via a single enable input and an oscillator/divider integrated circuit having crystal accuracy.
The present invention provides a system and a method for a low frequency initiation generator (e.g., high frequency pre-driver and signal conditioning circuitry) for use in a tire pressure monitoring system that achieves the desired frequency accuracy at a lower cost than conventional microprocessor based approaches via a single enable input and an oscillator/divider integrated circuit having crystal accuracy.
According to the present invention, for use in a tire pressure monitoring system, an initiator generator is provided comprising an oscillator/divider configured to generate an output signal in response to a switched, regulated voltage. The output signal has a fundamental frequency and a gating frequency.
Also according to the present invention, for use in a tire pressure monitoring system, a method of generating an initiator output signal is provided, the method comprising generating the output signal at a fundamental frequency in response to a switched, regulated voltage, and gating the output signal at a gating frequency.
Further, according to the present invention, a reduced power consumption tire pressure monitoring system initiator generator is provided comprising a switching circuit, a regulator, and an oscillator/divider. The switching circuit may be configured to generate a switched, unregulated voltage in response to a supply voltage and an enable signal. The regulator may be configured to generate a switched, regulated voltage in response to the unregulated voltage. The oscillator/divider maybe configured to generate an output signal in response to the switched, regulated voltage. The output signal has a fundamental frequency and a gating frequency.
The above features, and other features and advantages of the present invention are readily apparent from the following detailed descriptions thereof when taken in connection with the accompanying drawings.